Medical implant device with RFID tag and method of identification of device

ABSTRACT

The present invention is directed a method of making an interactive medical implant device including a radio frequency identification tag mounted to an implant, the tag being covered with a liquid impermeable seal. Identification of the RFID tag allows the physician to identify the specific identified implant with a an instrument model or patient database and allows the physician access to desired pertinent information regarding the medical implant device.

RELATED APPLICATIONS

This is a continuation of application Ser. No. 10/840,384 filed May 7,2004 issued as U.S. Pat. No. 7,333,013 on Feb. 19, 2008.

FIELD OF INVENTION

The present invention relates generally to a method of determining themanufacturer and model of a medical implant device after implantationand to construction of a medical implant device employing an RFID tag ona surface of the medical implant.

BACKGROUND OF THE INVENTION

Radiofrequency identification (RFID) is a type of automaticidentification technology that uses low wattage radio frequencytransmission for identification and data cataloguing. Radiofrequencyidentification (RFID) accelerates and facilitates the collection of dataand eliminates the need for human operations in the process.Radiofrequency identification (RFID) uses a reader and antenna arraywhich generates an EM-field from 850 MHz and 2 GHz and special tagswhich respond to the EM-field with the emission of data are attached orembedded to an object. There are no moving parts in radiofrequencyidentification (RFID) tags and readers and the systems are able tooperate effectively for extended periods without maintenance. Thebroadcasted radio frequency waves do not require a direct line of sightand locate objects in a three dimensional orientation and will travelthrough non-metallic materials.

Radiofrequency identification tags can be manufactured in variousshapes, sizes and configurations to suit an intended purpose. The nocontact, non-line-of-sight nature of the technology and its speed areimportant advantages of radiofrequency identification (RFID) systems. Atag and reader communicate in most cases with a response in less than100 milliseconds and radiofrequency identification (RFID) tags can beread through environmentally challenging conditions. The tags can workin a temperature range from −40° C. to +200° C. and are very durable andresistant to wear.

Passive radiofrequency identification (RFID) tags are typicallyread-only tags programmed with a unique set of data that cannot bemodified. This awards a high level of security. Passive radiofrequencyidentification (RFID) tags operate without a separate external powersource and obtain operating power generated from the exciter/reader.Passive tags are small, inexpensive, currently ranging from 25¢ to 50¢,and are expected to rapidly drop in price to 5¢ or less, and offer atheoretically unlimited operational lifetime. The tags will usually lastlonger than the object to which they are attached. A passiveradiofrequency tag does not add to any radiofrequency energy already inthe environment.

The development of radio frequency identification, called RFID,integrated circuitry and the adoption of a standardized EPC (electronicsproduct code) in late 2003 has permitted use of RFID tags in a widerange of applications. Use of such arrangements in a product package hasa wide variety of applications, including inventory, product processing,and tamper-indication, by monitoring the unique tag of the productpackage.

Radiofrequency identification tags are currently used for identifyingand locating animals. The application created for animal identificationis invaluable for farmers and pet owners. Animal tracking tags, insertedunder the skin of an animal, are only a few millimeters in size. Thespecific identification coded in tag is recorded in a database. Thissystem can monitor the animal's identity, location, type of diet, andliving conditions.

The microelectronics assembly is configured for radio frequencyinteraction by the provision of a suitable radio frequencyidentification (RFID) integrated circuit currently placed on a siliconchip the size of a grain of sand, an antenna, and one or moreinterconnections operatively connecting the circuit and the antenna. Theresulting assembly is commonly referred to as an RFID tag.

A radiofrequency identification system consists of three majorcomponents; comprising a reader (or interrogator), its associatedantenna and the transponders (radio frequency tags,/RFID Cards) thatcarry the unique programmed data and a computer or other system forprocessing data which is read by a reader.

The reader transmits a low-power radio signal generally, under 3 watts,through its antenna, that the tag receives via its own antenna to poweran integrated circuit (chip). Using the energy it gets from the signalwhen it enters the radio field, the tag will briefly converse with thereader for verification and the exchange of data. Once that data isreceived by the reader it can be sent to a controlling computer forprocessing and management.

A radiofrequency identification tag contains an electronic chip as aprincipal element, which is controlling the communication with thereader. This contains a section of memory functioning to store theidentification codes or other data; the memory being accessed at thecommunication time. The RFID tags can be attached or integrated in theobjects for identification.

The present invention is directed to a RFID tag embedded or mounted intoan implantable medical device for the identification of the medicaldevice as to manufacturer and model, for determination of globalpositioning of the device and identifying the instruments used to insertand remove the medical device. For example in total joint replacement,if the medical implant device is embedded with a radiofrequencyidentification tag (RFID) the surgical implantation of the device couldbe monitored by a global positioning navigational system. The implanteddevice could be serially monitored for any change in alignment, wear orloosening during the lifetime of the implant. Radiofrequencyidentification tags (RFID) are virtually impossible to copy.Radiofrequency identification technology can easily be adopted formedical confidentiality.

SUMMARY OF THE INVENTION

The present invention is directed toward a method for integratinglabeling of implantable medical devices and management of medicalinformation comprising the steps of: labeling the medical device with aradiofrequency identification device (RFID) and maintaining a medicalproduct database which associates the information, includingmanufacturer, type of implant, composition of implant, dimensions andmeasurements of implant, date of implantation, expiration date ifapplicable, type of instruments required for removal of implant and anyother type of data that may be beneficial, with the specific tagidentification for use by the physician or surgeon. The invention isalso directed toward a medical implant with an RFID tag and/or patientinformation database including patient name, address, medical history,treating physicians and institution, implanted device history.

It is an object of the invention to integrate radiofrequencyidentification (RFID) tags with implantable medical devices forautomatic device identification, monitoring and patient information.

It is another object of the invention to use radiofrequencyidentification (RFID) to provide more, exact implant information andimproved data acquisition regarding the implant.

It is still another object of the invention to use radiofrequencyidentification (RFID) of implantable medical devices to improve theaccess and control of critical medical information.

It is yet another object of the invention to specify and accuratelyidentify medical implants by using radiofrequency identification (RFID)tags placed upon the medical implant.

It is another object of the invention to provide radiofrequencyidentification (RFID) tags on implants that are substantiallymaintenance and error free.

It is another object of the invention to use radiofrequencyidentification (RFID) tags can be read through aqueous environment ofthe human body.

It is yet another object of invention to use radiofrequencyidentification (RFID) tags for monitoring of the implanted device.

It is another object of the invention to utilize radiofrequencyidentification (RFID) tags to control electrical stimulation, magneticstimulation, and administration of pharmaceutical or other therapeuticmodalities.

It is also an object of the invention to utilize radiofrequencyidentification (RFID) tags on medical implants to prevent counterfeitingof the implants or reusing the same in other patients.

It is yet another object of the invention to utilize radiofrequencyidentification (RFID) of implantable medical devices to facilitateincreased efficiency and productivity and of related patientinformation.

These and other objects, advantages and novel features of the presentinvention will become apparent when considered with the teachingcontained in the detailed disclosure along with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a medical implant with an RFID tagplaced thereon;

FIG. 2 is the medical implant of FIG. 1 implanted in the knee of a humanpatient;

FIG. 3 is a schematic representation of a medical implant RFID tag beingexcited by a reader and the identification information of the tag beingreceived; and

FIG. 4 is a schematic representation of a medical implant RFID tag beingexcited by a reader antenna with the specific implant information goingto data base and connected with product information and/or patientmedical information.

DETAILED DESCRIPTION OF THE INVENTION

While the present invention is susceptible of embodiment in variousforms as is shown in the drawings, and will hereinafter be described, apresently preferred embodiment, with the understanding that the presentdisclosure is to be considered as an exemplification of the invention,and is not intended to limit the invention to the specific embodimentsdisclosed herein.

The present invention is directed to a medical implant with anassociated RFID tag and a method of making an interactive medicalimplant which is sealed against liquid engagement with a radio frequencyidentification integrated circuit and associated antenna disposed on orwithin the implant. It is envisioned that the medical implants whichwill be used are those implants currently used in orthopaedics andcardiac procedures. Orthopaedic implants can consist of implants forjoint replacement, implants for hip replacement, implants for kneereplacement, implantable spinal cages, implantable spinal plates,implantable bone plates and bone screws; implantable rods, implantablenails, implantable bone screws, and implantable bone stents. Cardiacimplants can consist of cardiac and vascular stents, pacemakers anddefibrillation devices. One problem which occurs with pacemakers inaddition to the insertion and operation of same is a problem of sellingused pacemakers or recalled pacemakers for reinsertion into newpatients. The tagged medical implant facilitates its use for a varietyof applications, including product identification after implantation,recipient medical identification, storage and dissemination of productprocessing information, and product quality assurance, includingverification of manufacturers and original equipment. Use of medicalimplants formed in accordance with the present invention permitsefficient inventory control.

As illustrated in FIG. 2, the implant 10 which can be formed inaccordance with the present invention comprises seal or pouch 12 of awaterproof biocompatible plastic and an associated RFID tag 14 having anintegrated circuit 16 and antenna 18.

The RFID tag 14 includes a radio frequency identification integratedcircuit 16 in semiconductor chip form which is about the size of a grainof sand electrically connected to an antenna 18 placed in contrast withthe semiconductor circuit and mounted on a substrate 15. The RFID tagwhen placed on medical implant 10 is covered by a plastic seal orclosure 12 which acts as a moisture impermeable barrier protecting thecircuit against body fluids and damage. The chip is of standardconstruction and can be obtained from Alien Inc. or Matrix, Inc. whichare several of many chip manufacturers in the RFID chip industry. Theantenna 18 is operatively connected to the integrated circuit 16, withthe antenna cooperating with the integrated circuit to permit theintegrated circuit to be externally powered without physical connectionof a power supply thereto. The antenna 18 provides the desired radiofrequency interface with an associated radio frequency input/outputdevice 20 (FIG. 3) which can be configured to provide remote RF to thetag 14 and/or reading and retrieval of electronic information carried bythe integrated circuit 16 by the reader 22.

In accordance with the present disclosure, it is contemplated that theintegrated circuit 16 and antenna 18, and any associated components,including interconnections with the integrated circuit, be positionedwithin the seal 12 by disposition of the electronic components on asubstrate or liner 15 which is inserted into or covered by the seal 12.

External powering of the integrated circuit 16 precludes the need for aninternal power supply operatively connected to the integrated circuitfor providing electrical power thereto. However, for some configurationsof the present package (such as providing for capturing continuoushistorical data such as pressure and/or temperature), it may bedesirable to provide an alternate compact power supply 24, such asdiagrammatically illustrated in FIG. 3, which is operatively connectedto the integrated circuit 16.

The microelectronics assembly of the package can be configured toinclude one or more different types of compact-size (i.e., micro)sensing or medical treatment devices. Such sensing devices are in theform of a microchip circuit and may include, by way of example, apressure sensor 26, a temperature sensor 28, a chemical sensor 30 forsensing the presence of chemicals such as oxygen, and/or a biologicalsensor 32 for sensing the presence of microorganisms or a micro waveform generator 34 for generating electronic energy in the range of 20-50microamps to heal the area in the patient surrounding the implant 10.While the above noted sensors (26-32) are known in the art, the use ofsame with RFID tags has not been used. The configuration of the circuit16 and antenna 18 with one or more of the internal sensor devices notedabove greatly enhances versatile use of the medical implant, includingdetermination of the manufacturer of the implant, years afterimplantation, allowing the medical history of the patient to bedisplayed after reading the implant identification code,anti-counterfeiting and preventing the use of used medical implants. Anarray of sensors can be provided for certain applications, with thearray preferably integrated with radio frequency integrated circuit 16as is schematically shown in FIG. 3.

It is contemplated that the microelectronics assembly used in practicingthe present invention can be positioned on a mounting substrate 15inserted into the seal or pouch 12 made of durable biocompatible plasticwith the seal 12 in turn being secured by biocompatible cements,adhesives or glue to the sterile medical implant device. The RFID tag ispositioned in an area which is not subject to wear by engagement withsurrounding various body parts. The present invention particularlycontemplates that the mounting substrate for the microelectronics beprovided in the form of a substrate or liner 15 for insertion into theseal or pouch 12. The RFID tags 14 are preferably are inserted intopre-molded closures or seals 12 (as opposed to in situ molding of aliner). Closure manufacturers typically use thin sheet material rangingfrom 0.015 to 0.030 inches thick, depending upon the particular closuredesign. This material is supplied in large rolls, and is typically fedinto punching machines that punch circular discs from the liningmaterial, and substantially simultaneously insert the punched discs intoclosure shells. The remaining “skeleton” is typically re-ground andreturned to the material supplier for recycling and inclusion in futurerolls of lining material.

In such an arrangement, the sealing liner thus acts to provide thedesired sealing engagement between the closure assembly and the medicalimplant devices, with the microelectronics assembly thus securelypositioned within the closure, yet isolated from the fluids of the bodyafter implantation, in accordance with FDA requirements.

The present invention contemplates that various techniques can beemployed for providing the antenna 18, and associated interconnections,on the mounting substrate 15 for the electronics assembly. In one form,the antenna and interconnections are printed on the substrate 15 withelectrically conductive inks, with the printing steps selected from thegroup consisting of ink jet printing, silk screen printing, and offsetprinting. Alternatively, the antenna and interconnections can be formedby thin film deposition utilizing evaporation or sputtering on themounting substrate, with etching or laser machining of the thin filmeffected to form the antenna and interconnections.

Other techniques can be employed in accordance with the presentinvention for formation of the antenna and interconnections of themicroelectronics assembly. The antenna and interconnections can beformed by lamination on the mounting substrate, with the laminationetched or laser machined for formation of the antenna andinterconnections. Laser “writing” can be employed through the use oforgano-metallic gas which forms metal deposits when subjected to laserlight.

Mounting of the integrated circuit 16 on the mounting substrate can alsobe effected in various ways. As is known by those skilled in the art,the integrated circuit can be positioned active-side-down on themounting substrate with connection from the pads on the integratedcircuit made directly to the antenna or interconnection by soldering,stud-bump bonding or with a conductive adhesive, or active-side-up onthe substrate with connection from the pads on the integrated circuitmade directly to the antenna or interconnection with wire bonds.Formation of the microelectronics assembly can include the steps offirst positioning the integrated circuit on the mounting substrate, andforming a planarization layer over the integrated circuit. One or moreopenings are then formed in the planarization layer, such as byphotolithography or laser machining. The antenna is then formed on theplanarization layer, and interconnections formed through the openings inthe layer. The antenna and interconnections can be formed by metaldeposition followed by photolithography.

It is within the purview of the present invention that themicroelectronics assembly can be positioned on the mounting substrate byprinting the integrated circuit with semi-conductor inks as well as theassociated antenna and interconnections with electrically-conductiveinks directly on the.

To facilitate efficient use of the present interactive informationpackage, it is contemplated that the apparatus employed for insertion ofthe microelectronics and mounting substrate into the associated closurebe a so-called “smart machine”, that is, capable of reading informationfrom, and writing information onto, the microelectronics assembly. It isparticularly contemplated that this apparatus be configured for testingthe installed microelectronics prior to shipment of the RFID tags.

In operation as shown in FIG. 4 the sterile medical implant 10 isimplanted into a patient 11 with an RFID tag affixed thereto which has aspecific identifying code. The tag 14 is accessed by exciting the samein a field ranging from 870 Mhtz to 990 Mhtz at a power of up to threewatts generated by an outside powered antenna 20. The RFID tag 14 emitsa binary code which is read by a reader 22 and the reader 22 transmitsthe code to a computer 40 which accesses a data base 50 by the internet44 to link the code generated specific to the medical implant to aspecific manufacturer. Upon determination of the manufacturer of themedical implant and model of the medical implant, the surgeon orphysician can then click up the diagrams and schematics for the medicalimplant or alternatively link the code of the medical implant to adatabase 60 of a specific patient in which the device has been implantedand pull up the file history for the patient including records and/orpictures of the implant operation as well as the medical history of thepatient so that the data is stored and displayed on terminal 70 of theuser or physician.

The principles, preferred embodiments and modes of operation of thepresent invention have been described in the foregoing specification.However, the invention should not be construed as limited to theparticular embodiments which have been described above. Instead, theembodiments described here should be regarded as illustrative ratherthan restrictive. Variations and changes may be made by others withoutdeparting from the scope of the present invention as defined by thefollowing claims:

1. A method of making an interactive information medical implant takenfrom a group consisting of orthopaedic and cardiac implants, comprisingthe steps of: a) placing a fluid sealed microelectronics assemblymounted on a substrate, a sealing liner for sealing saidmicroelectronics assembly on said implant is placed over said substrateprotecting said microelectric assembly from fluid engagement, includingan RFID integrated circuit chip with a unique binary code correspondingonly to said medical implant, an antenna, and one or moreinterconnections operatively connecting said circuit and said antenna;b) exciting said RFID integrated circuit with energy emitted outside ofa patient in which the implant has been implanted causing said RFIDintegrated circuit to transmit said unique binary code to a receiverconnected to a computer; c) matching said received unique binary codewith an identical code in a database indicating a manufacturer of saidmedical implant to identify said medical implant; and d) obtaininginformation about the physical characteristics of said medical implant.2. The method of making an interactive information medical implant inaccordance with claim 1, wherein said orthopaedic implants consist ofimplants for joint replacement, implants for hip replacement, implantsfor knee replacement, implantable spinal cages, implantable spinalplates, implantable bone plates; implantable rods, implantable nails,implantable bone screws, and implantable bone stents.
 3. The method ofmaking an interactive information medical implant in accordance withclaim 1, wherein said cardiac implants consist of vascular stents,pacemakers and defibrillation devices.
 4. The method of making aninteractive information medical implant in accordance with claim 1,wherein step d). is replaced with the following step: transmittingschematics and part dimensions of said medical implant corresponding tothe matched received binary code from a computer to a physician uponidentification of the implant from the RFID binary code.
 5. The methodof making an interactive information medical implant in accordance withclaim 1, including: forming said antenna and said RFID integratedcircuit chip in electrical connection with independently energizedtemperature sensing means.
 6. The method of making an interactiveinformation medical implant in accordance with claim 1, including:forming said antenna and said RFID integrated circuit chip in electricalconnection with independently energized pressure sensing means.
 7. Themethod of making an interactive information medical implant inaccordance with claim 1, including: forming said antenna and said RFIDintegrated circuit chip in electrical connection with independentlyenergized chemical sensing means.
 8. The method of making an interactiveinformation medical implant in accordance with claim 1, including:forming said antenna and said RFID integrated circuit chip in electricalconnection with independently energized microorganism sensing means. 9.The method of making an interactive information medical implant inaccordance with claim 1, wherein said microelectronics assembly includesmicrowave generating means which generates electronic energy in therange of about 20 to about 50 microamps.